Nokia continues to expand its line-up of advanced feature phones with the Asha 205, with a dedicated Facebook button allowing users to more easily access the social networking site.

While Nokia is trying to revive its fortunes in the smartphone sector it is also upgrading its feature phone portfolio, and integrated social networking features are playing a key role.

On Monday, it followed up the launch of the 109 -- a US$42 phone on which users can access Twitter and Facebook from the home screen -- with the Asha 205.

The 205's Facebook button can be used to access the Facebook for Every Phone app, according Nokia.

Facebook introduced the Java-based Facebook for Every Phone app in July last year as way to allow more users to access the site and its messaging service using their mobile phones. It works just like the smartphone apps but has been implemented in a way that uses less data, according to Francisco Jeronimo, research manager at IDC.

Nokia isn't the first company to add a dedicated Facebook button. For example, last year HTC launched the Salsa and the ChaCha, two smartphones with dedicated Facebook buttons, but neither phone sold well.

"It is not the Facebook button that will make a difference; it is the device itself and its overall feature set. The button is more of a marketing tool," said Jeronimo.

Besides a dedicated Facebook button, the Asha 205 has a QWERTY keyboard, a 2.4-inch screen.

It runs Nokia's Series 40 software, with an email client and chat services from Google, Microsoft and Yahoo. Users can also download 40 free games from Electronic Arts over a GPRS or EDGE network.

On Monday, Nokia also launched the Asha 206, which has a numeric keypad and a 2.4-inch screen. The phone lacks the Facebook button, but does have an integrated WhatsApp client.

The Nokia Asha 205 and Asha 206 are both available with slots for one or two SIM cards.

They are also the first phones to have a new content sharing feature from Nokia called Slam.

The feature works with some Bluetooth-enabled mobile phones -- not iOS and Windows Phone-based smartphones, at present -- without the need to pair devices, and without the recipient needing a Slam-equipped phone. Users can share photos and videos using Slam.

The Nokia Asha 205 and Asha 206 will retail for about $62 without taxes and subsidies when they start shipping before the end of the year.

Nokia's struggles in the smartphone market are well documented. But the company has been doing better in the feature phone market, thanks in part to new touchscreen phones in the Asha family.

Excluding smartphones, unit sales increased by 4 percent when comparing the second and third quarter this year, Nokia reported in October.

"The segment is declining, but it still represents about 40 percent of worldwide shipments, and Nokia is the only company that is really innovating," said Jeronimo.